• 한국산림과학회지
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• 제94권5호통권162호
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• pp.334-337
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• 2005

Pine wood nematode isolates from Haman, Gyoungsangnam-do were cryopreserved with three different cryoprotectants (glycerol, ethylene glycol and dimethylsulfoxide), Nematode Growth medium (NGM) and M 9 buffer solution, respectively, and then survival rate, reproduction ability, and pathogenicity of stored nematodes were compared. Survival rates of juvenile was excellent in 15% glycerol solution as $72{\pm}5.3%$. The survival ability of nematodes at juvenile stage was more efficient than that of nematodes at adult stage. Pre-incubation treatment at $4^{\circ}C$ before storing in liquid nitrogen didn't affect the survival ability of pine wood nematode. When the reproduction ability of nematodes was confirmed on Botrytis cinerea agar plates at $28^{\circ}C$ incubator, there was no difference between cryopreserved and non-cryopreserved. Pathogenic ability of cryopreserved nematodes was also evaluated and confirmed by artificially inoculating them on 2-year old red pine seedlings.

• 한국응용곤충학회지
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• 제29권1호
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• pp.14-19
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• 1990

부산, 경남, 경북, 전남, 전북 22개 지역 19수종 238본의 고사목에서 1989년 4월부터 9월까지 선충류와 곤충류를 조사한 결과, 소나무 재선충은 부산지역에서만 검출되었으며, 어리소나무 재선충은 진주와 진해에서 분포가 확인되었다. 고사목에서 분리.동정된 선충류는 9속 13종이었으며 6속은 미동정되었다. 동정된 선충 중 Diplogasteroides dimidius, Rhabdontolaimus adephagus, R.janae, Mikoletzkya diluta, M. ruminis, m. langcauda, Parasitorhabditis hylurgi, Panagrolaimus concolor, Panagrodontus dentatus, Prothallonema intermedium, Macrolaimus canadensis는 우리나라 미기록종이다. 한편, 고산목에서 채집된 곤충은 5목 9과 25속 27종이었는데 딱정벌레목이 3과 19속 22종으로 가장 많았다. 그중 나무종이 10속 12종으로 빈번히 채집되었으며, Hypothenemus eruditus가 꽃싸리, 싸리, 조록싸리, 만리화, 닥나무에서 채집되어 새 기주로 추가되었다. 소나무 재선충의 매개충인 솔수염하늘소는 복부에서의 선충 검출수가 가장 많았으며, 성충 한마리당 선충 보유수는 최대 127,535마리, 최소 2,616마리, 정균 42,817마리였다.

• The Plant Pathology Journal
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• 제23권2호
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• pp.70-75
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• 2007

We conducted an inoculation test using nine open-pollinated families of pine trees to evaluate their susceptibility and mortality in different densities of pine wood nematode. Three-year-old nine open-pollinated pine families were inoculated with Bursaphelenchus xylophilus at levels of 3,000, 5,000, and 7,000 nematodes/seedling in greenhouse. There were no distinct patterns in latent period among three densities of B. xylophilus in all families. Most families showed the first disease symptoms of needle discoloration within 12-15 days after inoculation. However, open-pollinated progenies of Pinus densiflora showed the longest latent period because none of one-year-old needles were wilted until 14 days after inoculation with 5,000 and 7,000 nematodes. One-year-old needles were wilted earlier than current needles in all tested families with all densities of B. xylophilus. Current needles were not wilted until 14 days after inoculation in all seedlings. The mortality of all seedlings rapidly increased from 35 days to 49 days after inoculation, and all died within 80 days except two seedlings. A 3,000 nematodes/100 ${\mu}L$ with sterilized distilled water are enough to screen 3-year-old pine seedlings for resistance to B. xylophilus.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.105-112
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• 2017

The distribution and form of pine wood nematode (PWN) were investigated in Jinju-si and Sacheon-si areas, where infested with pine wilt disease (PWD). The average PWN population per g of the tubulation part in the wilted Japanese balck pine were 381.2 and 341 in Jinju-si and Sacheon-si, respectively. The PWN population per g of affected Japanese black pine with wilt rate below 60% were 556 and 518 in Jinju-si and Sacheon-si, respectively. The ratios of PWN and other plant-parasitic nematode in the wilted Japanse black pines were 48% vs. 52% in Jinju-si and 53% vs. 47% in Sacheon-si after exposure to PWD for 1 year. The survivorship of pine wood nematode in the sampled trees after 1 year was 0-10% in the Jinju-si area and 5-20% detected in the Sacheon-si area. In the forest areas affected by PWN, the highest survival rates were 37.2% and 39.8% at 25 cm diameter at breast height (DBH) in Jinju-si and Sacehon-si, respectively, while the highest wilt rates were 30.5% and 28.3% at 30 cm DBH in Jinju-si and Sacehon-si, respectively.

• 한국산림과학회지
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• 제97권6호
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• pp.570-575
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• 2008

본 연구는 국내산 4년생 해송을 대상으로 소나무재선충을 인공접종하여 나타나는 병징의 발달과 묘목내 수분함량 및 선충밀도의 변화를 조사 및 분석하여 소나무재선충에 의한 생리적 변화과정 구명에 사용될 수 있는 기초 자료로 활용되고자 수행되었다. 소나무재선충 인공접종 후 20일을 기점으로 외부적으로 잎의 변색 그리고 내부적으로 접종 부위 위 아래의 목부 건조 및 수 갈변 현상이 나타났다. 그러나 접종 후 10일에 대조구 묘목과 접종목의 목부 및 피층의 건조상태는 차이를 나타내어 목부 건조는 접종 후 10일 경부터 진행이 되고 있음을 알 수 있었다. 소나무재선충 밀도는 접종 후 5일과 10일 사이에서 소폭의 증가를 보였으나 외부적 또는 내부적 피해증상이 나타난 10일과 20일 사이에서는 급격한 증가를 보였다. 소나무재선충 접종 후 시간이 경과함에 따라 감염목의 줄기수분함량 및 당년생 잎과 줄기의 상대수분함량은 꾸준히 감소하였다. 소나무재선충의 개체 수가 증가함에 따라 줄기수분함량, 당년생 가지 및 잎의 상대수분함량이 유의적으로 감소하여, 소나무재선충 증식은 병 발달 및 수체내 목부의 수분건조 현상과 밀접한 상관관계를 보이지만 묘목의 고사와 함께 재선충 번식이 현격히 줄어드는 것으로 나타났다.

• The Plant Pathology Journal
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• 제29권3호
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• pp.344-349
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• 2013

Intraspecific variation in morphometry of pine wood nematodes Bursaphelenchus xylophilus and B. mucronatus in relation to geographical locations in South Korea was investigated using morphometric characters (body length, a, b and c ratio, stylet length, and spicule length for a male nematode and V (%) value for a female nematode). B. xylophilus was isolated from Pinus thunbergii in Jinju (1998), Ulsan (2000), Yangsan (2000), Mokpo (2001) and Jeju (2004), and from P. densiflora in Gumi (2001). B. mucronatus was isolated from P. thunbergii in Jinju (1991) and from P. densiflora in Milyang (2001). The body length of male and female B. xylophilus had the highest coefficient of variability and showed significant differences among geographical locations. The V (%) value for female B. xylophilus showed the lowest coefficient of variability, changing little with geographical area and host plant. All morphometric characters in B. mucronatus except for stylet length and female body length showed no significant differences between locations or hosts, suggesting they may not be affected by geographical area or host plant.

• Journal of Ecology and Environment
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• 제38권1호
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• pp.85-93
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• 2015

In 2013, the epidemics of pine wilt disease caused by the pine wood nematodes (Bursaphelenchus xylophilus) resulted in damages to the forests of black pine (Pinus thunbergii Parl.) trees in Jeju Island, Korea. Among the affected trees, an old black pine tree at Cave Temple on Mt. Sanbangsan was included and died due to the prevalence of pine wilt disease. The tree was on Mt. Sanbangsan, which was designated as a National Scenic Place with the Number 77 and was believed to be more than 400 years old in age. By examining the disc of the tree stem obtained from the height of 2 m, we counted the tree rings from 4 different directions and cross-dated the readings by comparing the records of drought simulated from the BROOK Model. Our analysis indicates that the tree seems to have grown since late 1860s. Contrary to the belief of the general public, we can conclude that the age of the tree was estimated to be at maximum 150 years, which means that it was not the same old tree as was shown in the painting of the Tam-Ra-Sun-Ryeok-Do (an old painting book for the Inspection Tour of Jeju Island) published in 1702. Discussion was extended to the life history of the tree in growth and leaning and the measures to protect the tree species from the damages of the pine wilt disease caused by pine wood nematodes.

• The Plant Pathology Journal
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• 제39권1호
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• pp.75-87
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• 2023

The pine wood nematode (PWN), Bursaphelenchus xylophilus is a well-known devastating pathogen of economic importance in the Republic of Korea and other countries. In the Republic of Korea, trunk injection of nematicides is the preferred method of control. In this study, the efficacy of 16 locally produced formulations of emamectin benzoate against the PWN are compared through determining their sublethal toxicities and reproduction inhibition potentials. Nematodes were treated with varying concentrations of the tested chemicals in multi-well culture plates, and rates of paralysis and mortality were determined after 24 h. Reproduction inhibition potential was tested by inoculating pre-treated nematodes onto Botrytis cinerea, and in pine twig cuttings. Despite the uniformity in the concentration of the active ingredient, efficacy was contrastingly different among formulations. The formulations evidently conformed to three distinct groups based on similarities in sublethal activity (group 1: LC₉₅ of 0.00768-0.01443 mg/ ml; group 2: LC₉₅ of 0.03202-0.07236 mg/ml, and group 3: LC₉₅ of as high as 0.30643-0.40811 mg/ml). Nematode paralysis generally occurred at the application dose of 0.0134-0.1075 ㎍/ml, and there were significant differences in nematode paralysis rates among the products. Nematode reproduction was only evident at lower doses both on B. cinerea and pine twigs, albeit the variations among formulations. Group 1 formulations significantly reduced nematode reproduction even at a lower dose of 0.001075 ㎍/ml. The variations in efficacy might be attributed to differences in inert ingredients. Therefore, there is need to analyze the potential antagonistic effects of the large number of additives used in formulations.

• The Plant Pathology Journal
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• 제29권1호
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• pp.116-122
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• 2013

To evaluate the mechanisms of pathogenicity and nonpathogenicity of Bursaphelenchus xylophilus and B. mucronatus isolated in South Korea, we used 4-year-old P. thunbergii seedlings and 20-cm long one-year-old stem cuttings of 5-year-old Pinus thunbergii, and studied distributions and multiplications of pine wood nematodes after inoculation. The distributions of B. xylophilus in the 20-cm pine stem cuttings were not significantly different from that of B. mucronatus. Conversely, the proliferation rate of B. xylophilus on mycelial mats of Botrytis cinerea was significantly different from that of B. mucronatus. The study using 4-year-old P. thunbergii seedlings also showed that B. mucronatus can migrate to distal portions of the pine seedlings the same as B. xylophilus, but the populations of B. xylophilus remaining in the pine seedlings were relatively larger than those of B. mucronatus. Therefore, we concluded that the pathogenicity of B. xylophilus could be strongly influenced by its ability to multiply.

• 한국응용곤충학회지
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• 제57권1호
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• pp.7-13
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• 2018

소나무재선충(pine wood nematode, PWN) 감염 소나무를 현장에서 신속하게 진단을 할 수 있는 방법은 현재 없다. 본 연구에서는 PWN특이적인 항원으로 알려진 PWN-GaLectin을 baculovirus발현체계로 발현시켜서 총 1,464개의 fusion hybridoma 세포 주 라이브러리를 제작 하는 항원으로 이용하였다. 총 1,464개의 fusion hybridoma 세포 주 중, PWN-GaLectin에 대한 높은 반응을 보이는 62개의 fusion hybridoma 세포 주를 선별했다. 이들 중, 표준 PWN 감염소나무 PBS추출물과 PWN 단백질 추출물에 강한 반응을 보이는 세포 주 12개를 선별하여 단클론 항체(monoclonal antibody, Mab) 분비세포 주 확립을 위한 limited dilution을 실시하였다. Mab분비세포 주 확립을 위해서 표준 PWN 감염소나무 추출물에 대한 반응이 표준 정상 소나무 추출물 보다 높은 세포 주들을 선별했다. 그리고 추가로 PWN 단백질 추출물에 대해서 3종의 비 병원성 선충 단백질 추출물 보다 높은 반응을 보이는 세포 주들도 선별, 확립했다. 본 연구에서 확립된 Mab들을 우리는 현장과 실험실에서 사용할 수 있는 신속진단키트의 개발에 이용할 수 있을 것이다.